Epoxidized soybean oil is a product widely used for stabilization of polyvinyl chloride. Mixtures containing this stabilizing agent are used particularly for making packaging materials, such as wrapping film, by extrusion.
To increase the productivity of the extruders, manufacturers of such packaging materials use extruder temperatures as high as possible. It is therefore necessary for the different constituents of the polyvinyl chloride mixture to be stable at these high temperatures.
However, it is known that when epoxidized soybean oil is brought to a high temperature, undesirable decomposition reactions occur followed by condensations and polymerizations reflected by a loss of the oxirane oxygen and a considerable increase in the viscosity of the soil. Thus, PVC compositions containing epoxidized soybean oil are sometimes ruined during high temperature extrusion.